首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5475篇
  免费   1059篇
世界政治   2篇
外交国际关系   1篇
法律   6417篇
中国政治   36篇
政治理论   11篇
综合类   67篇
  2024年   22篇
  2023年   82篇
  2022年   70篇
  2021年   87篇
  2020年   279篇
  2019年   276篇
  2018年   292篇
  2017年   406篇
  2016年   517篇
  2015年   372篇
  2014年   489篇
  2013年   497篇
  2012年   432篇
  2011年   576篇
  2010年   467篇
  2009年   461篇
  2008年   368篇
  2007年   332篇
  2006年   294篇
  2005年   58篇
  2004年   38篇
  2003年   40篇
  2002年   30篇
  2001年   17篇
  2000年   9篇
  1999年   1篇
  1998年   4篇
  1997年   11篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1990年   1篇
  1988年   1篇
排序方式: 共有6534条查询结果,搜索用时 15 毫秒
181.
This study investigated the characteristics of abuse suffered by children, the dimensions of the psychiatric effects associated with abuse, and the factors affecting these. One thousand two cases aged under 18, exposed to sexual abuse, and referred over a 7‐year period were assessed. Girls represented 80.8% of cases, and the numbers rose with age. The aggressors were all male, and 88.2% were known to their victim. Approximately half the children were exposed to sexual abuse involving penetration. Psychological pathology was identified in 62.1%. Female gender, the presence of penetration, physical violence, and incest significantly increased the development of psychological pathology. Levels of awareness in people close to and trusted by the child must be raised to minimize the adverse effects of trauma in the long term, preventive measures must be taken, and medical and social support units from which victims can receive assistance need to be established.  相似文献   
182.
The extraction of DNA from human skeletal remains applied to forensic, and evolutionary studies do not exclude risks, which are to be evaluated when working with unique specimens that could be damaged or even destroyed. In the present study were evaluated several nondestructive methods for recovering DNA instead of the most currently used pulverization method. Three different procedures to access inside the dental pieces (occlusal perforation, cervical perforation, and cervical cut) have been compared with the aim of recovering as many cell remains as possible to carry out a DNA extraction. Given the DNA quantitation results, a method was proposed that consists of a cervical cut to facilitate the access to the pulp cavity and a subsequent filing of the root canals down to the apex of the dental root. This methodology allows the recovery of both mitochondrial and nuclear DNA, with the minimum deterioration for the dental pieces.  相似文献   
183.
Contact and close‐range gunshot injuries can produce bloodstains on the shooting hand and weapon. In this study, backspatter was analyzed in experimental horizontal pistol shots into blood‐filled sponges. The shooting distances were set between 0 and 45 cm. With increasing shooting distance, there was a significant decrease in the degree of backspatter. Microspatter could be detected on the weapon and shooting hand up to a shooting distance of 40 cm. They were predominantly located on thumb and index finger as well as the radial dorsal aspects of the hand. Fine spray of microspatter combined with elongated droplets in the shape of exclamation marks was found at contact and 2‐cm distance shots. An angular calculation based on the shape of the bloodstains was possible up to a shooting distance of 2 cm. No bloodstains were detected beyond 45 cm.  相似文献   
184.
Maceration techniques employed in forensics must be effective without compromising the bone's integrity and morphology, and prevent destruction of evidence. Techniques must also be fast, safe, easily obtainable and inexpensive; not all techniques currently employed are appropriate for forensic use. To evaluate the most suitable approach, seven techniques including current and new methodologies were applied to fresh, fleshed porcine ribs exhibiting cut marks. A sample size of 30 specimens per technique was examined under scanning electron microscopy at the cut mark and the surrounding uncompromised regions; a scoring system of effectiveness was applied. The previously unpublished microwave method fared best for bone and cut mark preservation. Sodium hypochlorite destroyed cut marks, and was deemed unsuitable for forensic analysis. No single technique fulfilled all criteria; however, this study provides a benchmark for forensic anthropologists to select the most appropriate method for their situation, while maintaining the high standards required by forensic science.  相似文献   
185.
The aim of this study was to clarify whether positive results for prostate‐specific antigen (PSA) and acid phosphatase (AP) occur in postmortem swabs from the genito‐anal region in males (n = 80; 4 regions) and females (n = 20; 3 regions) and to calculate the positive predictive value (PPV) concerning the presence of spermatozoa. In male subjects, the highest incidence of positive test results was found in urethral swabs (PSA 76%, AP 71%) and the lowest frequencies appeared in perianal and rectal swabs (15–20%). Microscopic evaluation for spermatozoa was positive between 39% in urethral swabs and 1% in rectal swabs. PPV regarding positive identification of spermatozoa was 33.3% for PSA and 31.5% for AP. The combination of both tests yielded a PPV of 38.2%. In female cases, no spermatozoa were identified, and one case was PSA‐ and AP‐positive in perianal swabs. Our findings indicate that PSA and AP tests are of limited value for the postmortem detection of spermatozoa in male subjects.  相似文献   
186.
Odontological identification consists of the comparison of antemortem dental information regarding a missing person with postmortem data from an unidentified corpse or human remains. Usually, the comparison concerns morphologic features that the operator chooses among all the visible characteristics because of inter‐individual uniqueness; for this reason, implants can be of enormous assistance. A case concerning the recovery of a burnt oral implant, connected to a bone fragment, among 2780 charred bone fragments, suspected to have belonged to a victim of homicide, is presented to demonstrate that dental implants and their site of bone integration represent a very precious element for personal forensic identification. Because of their morphological invariability in time and because of their morphologic uniqueness, they were used as evidence to associate unidentified human charred remains to a missing person where DNA analysis failed to do so. The case illustrates the fundamental contribution, not yet described in literature, given by the clinical aspects of tooth replacement with dental implants to a forensic discipline. Clinical practitioners should therefore be aware of the great importance of their work and of dental records in a forensic identification scenario.  相似文献   
187.
The traditional histology method typically employed by forensic anthropologists involves plastic embedding of undecalcified bone. The embedded sample is then cut by a diamond blade saw and ground to the required thickness of ~50–100 microns using a grinder. There are several limitations to this method: Cement lines may be blurred; depth‐of‐field artifacts may result from viewing thick sections; and medicolegal offices with limited budgets may not be able to invest in additional equipment or training for this method. A silver nitrate stain modification of the standard histology preparation technique of decalcified bone is presented. The benefits of this technique are that: Cement lines are viewed clearly; no depth‐of‐field artifacts are present; and because this is a modification of the standard technique used by histology laboratories typically employed by medicolegal offices, no additional equipment or training is required.  相似文献   
188.
目的研究微视野仪与视诱发电位检测结果与最佳矫正视力的相关性,探索检测眼底黄斑病变者最佳矫正视力的途径。方法对62例黄斑病变者(黄斑病变组,62眼)及18例健康志愿者(对照组,36眼)进行最佳矫正视力、微视野仪及视诱发电位的检测。结果 (1)微视野仪检测示黄斑病变组视网膜平均敏感度、固视百分率均低于对照组,置信椭圆面积均大于对照组;视诱发电位检测示0.5周期/度(circle per degree,cpd)及2 cpd P100波振幅较对照组降低,潜伏期延长(P0.05)。(2)黄斑病变组最佳矫正视力与其视网膜平均敏感度、置信椭圆面积及黄斑中心2°、4°固视百分率之间呈正相关性(P0.05)。视网膜平均敏感度与P100波的振幅呈线性相关(P0.05)。(3)多元线性回归方程为y=0.053 x1+0.008 x3+3.897(y为最佳矫正视力,x1、x3分别为视网膜平均敏感度与2 cpd P100波振幅)。结论联合使用微视野仪与视诱发电位有助于判断黄斑区视网膜病变患者的客观最佳矫正视力。  相似文献   
189.
目的观察大鼠过敏性休克死亡后血清IgE、类胰蛋白酶的变化规律,探讨其与死亡时间(PMI)、尸体及样本保存环境的相关性。方法建立大鼠过敏性休克死亡动物模型并分组,包括室温组、冷藏组、冷冻组、人工溶血组、血清样本保存组,并设立对照组。大鼠处死采血后,按离心后上层血清颜色进行溶血程度分级。通过ELISA法检测血清IgE、类胰蛋白酶在各组中的质量浓度。结果大鼠过敏性休克死亡后血清IgE、类胰蛋白酶水平明显高于对照组;室温、冷冻保存下血清IgE、类胰蛋白酶随PMI的不同有明显变化,冷藏保存下浓度相对稳定;随溶血程度的增加,血清IgE、类胰蛋白酶水平均呈升高趋势。样本不同温度条件下保存25 d,血清IgE、类胰蛋白酶无明显变化。结论大鼠过敏性休克死后血清IgE、类胰蛋白酶明显升高,但其水平受PMI、环境温度影响较大,尤其是室温或冷冻保存。  相似文献   
190.
目的使用多层螺旋CT(multi-slice spiral computed tomography,MSCT)技术对高坠伤的损伤特征进行观察分析,并通过对高坠伤的分析和观察重建高坠过程,从而探讨MSCT在分析高坠伤案例中的应用价值。方法以真实的高坠伤案例为对象,分别运用MSCT平扫、三维重建技术对尸体进行全面检查,联合运用系统尸体解剖分析高坠伤死亡方式等特点,比较尸体解剖和MSCT在获取损伤信息方面的差异。结果MSCT扫描结合三维重建,发现全身多部位骨折以及肝破裂,尸体解剖与影像学检查结果相对应,推断死亡原因为高坠致全身多发伤。结论 MSCT在高坠伤案件致伤方式分析中可作为传统尸体解剖的补充手段。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号